Ativação de neurônios encefálicos pela estimulação elétrica nervosa transcutânea (TENS) em ratos

• Ano de defesa: 2013
• Autor(a) principal: Guimarães, Elisama de Campos
• Orientador(a): Santana, Josimari Melo de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Programa de Pós-Graduação: Pós-Graduação em Ciências Fisiológicas
• Palavras-chave em Português: Estimulação elétrica transcutânea do nervo; Dor; Analgesia; Eletroterapia; Fisioterapia; Imunofluorescencia
• Palavras-chave em Inglês: Analgesia; Electrotherapeutics; Pain; Physical therapy; Therapeutics, Physiological; Transcutaneous electrical nerve stimulation
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::FISIOLOGIA
• Link de acesso: https://ri.ufs.br/handle/riufs/3973

Transcutaneous Electrical Nerve Stimulation (TENS) has been widely used by physical therapists for pain management, though other non-analgesic properties have been cited. A series of studies have shown that TENS acts through both central and peripheral mechanisms. However, little is known about the mechanisms of action of TENS. So, in order to improve the research on such mechanisms, this work aimed to identify brain areas activated by different protocols of TENS stimulation in non-hyperalgesic rats. Fos protein expression in neurons has been used as a marker of neural activity. A total of 15 male Wistar rats weighing between 250 to 350 g received a single administration of TENS with low (4 Hz) or high (100 Hz) frequency and sensory (absence of muscle contraction) or motor (muscle contraction) intensity of stimulation. Ninety minutes after stimulation, the animals were euthanized under general anesthesia and their encephalons were perfused and sectioned to perform the immunofluorescence for Fos technique. Then images were captured and analyzed. The animals were split into five groups (n=3, per group): control, whose animals did not received electrical stimulation, low frequency TENS at sensory level, low-frequency TENS at motor level, high frequency TENS at sensory level and high frequency TENS at motor level. After analyzing the images, a significant higher c-Fos expression was found in the electrically stimulated animals when compared to the control group at the following brain areas: preoptic area (p=0.003), insular cortex (p=0.01), motor cortex (p=0.009), prefrontal cortex (p=0.003), thalamic paraventricular nucleus (p=0.003), endopiriform cortex (p=0.01), inferior colliculus (p<0.005), entorhinal cortex (p.0.0003), secondary somatosensory cortex (p.0.0003) and olfactory tract (p.0.0003) in a manner dependent from both frequency of stimulation and intensity of current. Thus, one suggest that TENS activated several important encephalon regions, which are involved in neural function such as cognition, memory, cardiovascular regulation and motor control; however, we cannot restrict these areas as the only ones that are influenced by TENS stimulation. These results are of great relevance, because it open perspectives on new and different neurobiological actions of TENS and its possible clinical applicability and therapeutic efficacy for addressing clinical situations unrelated to analgesia, allowing wider direction for further studies.